Modular Truss

ABSTRACT

A method of fabricating a truss section is provided. Cross-bars are connected to truss chords, each cross-bar extending between an associated pair of truss chords, the cross-bars located adjacent to an end of the truss section. An end plate is coupled to the cross-bars after the cross-bars have been connected to their truss chords. The end plate has apertures and ear portions. Each ear portion extends from the end plate to cover an end of a truss chord. The apertures align with corresponding apertures in an end plate of an adjacent truss section. The apertures receive connectors that also pass through the corresponding apertures to fixedly couple the two truss sections. The method may also include coupling a rig bar between truss chords. The rig bar may receive a removable coupler to suspend the truss from above.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 15/703,904 filed Sep. 13, 2017 by Michael Wells, et al. entitled, “Modular Truss”, which is incorporated by reference herein as if reproduced in its entirety.

TECHNICAL FIELD

The present application relates generally to truss structures and, more specifically, to a modular truss.

BACKGROUND

Truss structures may be used to support lights, speakers, screens, scenery, drapes, or other equipment in performance or display spaces. For ease of transporting such truss structures, the structure may be assembled on site from modular segments that are bolted or otherwise coupled together. The assembled truss structure may then be attached to an overhead building structure or to ground-based overhead supports and raised above the performance or display space.

SUMMARY OF THE DISCLOSURE

In accordance with a first aspect of the present disclosure, there is provided a method of fabricating a truss section. The method includes connecting a plurality of cross-bars to a corresponding plurality of truss chords, each cross-bar extending between an associated pair of truss chords, the cross-bars located adjacent to an end of the truss section. The method also includes fixedly coupling an end plate to the cross-bars after the plurality of cross-bars have been connected to the corresponding plurality of truss chords. The end plate has a plurality of apertures and a plurality of ear portions. Each of the ear portions extends from the end plate to cover a corresponding end of one of the truss chords. The apertures are configured to align with corresponding apertures in an end plate of an adjacent truss section. The apertures are operable to receive connectors that also pass through the corresponding apertures to fixedly couple the truss section to the adjacent truss section.

In accordance with a second aspect of the present disclosure, there is provided a method of fabricating a truss section. The method includes connecting a plurality of cross-bars to a corresponding plurality of truss chords, each cross-bar extending between an associated pair of truss chords. The cross-bars are located adjacent to an end of the truss section. The method also includes fixedly coupling a first end of a rig bar to a first truss chord, and fixedly coupling a second end of the rig bar to a second truss chord. The rig bar includes an aperture adapted to receive a portion of a removable coupler without the use of tools. The removable coupler is operable to suspend the truss from above. The method further includes fixedly coupling an end plate to the cross-bars after the cross-bars have been connected to the truss chords. The end plate has a plurality of apertures and a plurality of ear portions. Each of the ear portions extends from the end plate to cover a corresponding end of one of the truss chords. The apertures are configured to align with corresponding apertures in an end plate of an adjacent truss section. The apertures are operable to receive connectors that also pass through the corresponding apertures to fixedly couple the truss section to the adjacent truss section.

Other technical features may be readily apparent to one skilled in the art from the following figures, descriptions and claims.

Before undertaking the DETAILED DESCRIPTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “controller” means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts:

FIG. 1 presents an isometric view of a conventional truss section;

FIG. 2 provides an isometric detail view of connection elements used to suspend a conventional truss;

FIG. 3 presents an isometric view of an end of a conventional truss section showing connection pieces for coupling truss sections;

FIG. 4 presents an isometric view of an end of a conventional truss section showing a second type of connection pieces for coupling truss sections;

FIG. 5 presents an isometric detail view of a truss section according to a first embodiment of the disclosure;

FIG. 6 provides an isometric detail view of connection elements used to suspend a truss according to the first embodiment of the disclosure;

FIGS. 7 and 8 present detail views of a portion of the truss section of FIG. 5;

FIGS. 9A and 9B provide isometric views of a truss section according to a second embodiment of the disclosure; and

FIGS. 10A and 10B provide isometric views of a truss section according to a third embodiment of the disclosure.

DETAILED DESCRIPTION

FIGS. 1 through 10B, discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged modular truss section.

FIG. 1 presents an isometric view of a conventional truss section 100. The truss section 100 includes four tubular chords extending longitudinally along the truss section. Tubular braces extend horizontally and diagonally between the chords and, typically, are welded to the chords. As will be described in greater detail with reference to FIGS. 3 and 4, each end of the truss section 100 includes cross-bars connecting pairs of chords at the ends of the chords and connection plates welded to the cross-bars. The truss section 100 may be placed end-to-end with a similar truss section and bolts or other connectors placed through adjacent holes in the connector plates to clamp the two truss sections together. In this way, a longer truss may be assembled from truss sections.

FIG. 2 provides an isometric detail view 200 of connection elements used to suspend a conventional truss 202. A wire rope 204 may be used to hang the truss 202. The wire rope is typically fitted with an eye. To form the eye, the wire rope is passed through a ferrule and turned back on itself. The ferrule is then swaged to bind the two pieces of rope. The wire rope may be passed around a thimble to form the eye. While FIG. 2 shows a wire rope, it will be understood that trusses may additionally or alternatively be hung from a chain. Such a chain may alternatively be fitted with a hook with a spring loaded guard over the opening of the hook, rather than an eye fitting.

A sling 206 is passed beneath the two top chords of the truss 202 at a panel point and the body of a shackle 208 threaded through the ends of the sling. A threaded pin is passed through one lug of the shackle 208, through the eye of the wire rope 204, and screwed into the other lug of the shackle 208. Typically, at least two wire ropes are used to hang the truss 202, each wire rope with an associated sling, where the wire ropes are positioned above panel points of the truss so as to hang vertically. A panel point is a location on a truss where diagonal members are welded next to each other on the truss chords.

Many safety codes require a second, non-flammable tie between the shackle 208 and the truss 202, to keep the truss 202 from falling if the sling 206 should fail, for example in a fire. For such a safety tie, a second wire rope 210 may also be passed beneath the two top chords of the truss 202 and coupled to the shackle 208 using a second shackle 212. In this way, should the sling 206 fail, the truss 202 will still be supported from the wire rope 204 by the shackle 208, the second shackle 212, and the second wire rope 210.

FIG. 3 presents an isometric view of an end of a conventional truss section 300 showing connection pieces 306A and 306B for coupling truss sections. The other end of the truss section 300 is similarly arranged to the end shown in FIG. 3.

The truss section 300 includes chords 302 and cross-bars 304 located near the ends of the chords 302. Each cross-bar 304 extends from one chord 302 to another chord 302. Welded to the cross-bars 304 are connection pieces 306A and 306B. The connection pieces 306A and 306B are mirror image L-shaped brackets. A first leg of connection piece 306A is welded to an end-facing surface of a vertical cross-bar 304. Each end of a second leg of the connection piece 306A is welded to a cross-truss facing surface of a corresponding one of the two horizontal cross-bars 304. The connection piece 306B is similarly welded to the other vertical cross-bar and the two horizontal cross-bars.

The connection pieces 306A and 306B have apertures 308 for receiving bolts to clamp the truss section 300 to a similar truss section abutted end-to-end. The cross-bars 304 are set back from the ends of the chords 302 by approximately the thickness of the first legs of the connection pieces 306A and 306B. As such, the exposed faces of the first legs of the connection pieces 306A and 306B are approximately coplanar with the ends of the chords 302.

FIG. 4 provides an isometric view of an end of a conventional truss section 400 showing alternative connection pieces 406 for coupling truss sections. The connection pieces 406 are L-shaped brackets having a triangular first leg and a rectangular second leg and are located in the corners of the rectangle formed by the ends of the chords and the cross-bars 404. The first leg of a connection piece 406 is welded along two edges to end-facing surfaces of two adjacent cross-bars 404, while opposite edges of the second leg are welded to cross-truss facing surfaces of the same two cross-bars 404.

Similar to the connection pieces 306A and 306B described with reference to FIG. 3, the connection pieces 406 have apertures for receiving bolts to clamp the truss section 400 to a similar truss section abutted end-to-end. Also similarly, the cross-bars of the truss section 400 are set back from the ends of the chords by approximately the thickness of the first legs of the connection pieces 406.

As may be seen in FIGS. 3 and 4, cross-bars may have rectangular or circular cross sections. In other embodiments, cross-bars may have other suitable cross sections. In still other embodiments, the chords may have rectangular or other suitable cross sections. The apertures in the connection pieces described with reference to FIGS. 3 and 4 are typically located in a standard pattern and spacing relative to the chords of the truss sections so that, when bolts are placed through the apertures to clamp truss sections together, adjacent chords are substantially co-axially aligned.

FIG. 5 presents an isometric detail view of a truss section 500 according to a first embodiment of the disclosure. The truss section 500 includes chords 502 along the top and bottom faces of the truss section 500 and rig bars 520 between top and bottom pairs of chords 502. The rig bars 520 include apertures 522. The rig bars are located at panel points of the truss section 500 and can be used to hang the truss section 500.

While the truss section 500 has a rig bar 520 at each panel point, in other embodiments a truss section may have only one rig bar at a central panel point or any other desired number of rig bars at desired panel points. While the truss section 500 has rig bars 520 extending between both the top pair and bottom pair of chords 502, in other embodiments, a truss section according to the disclosure may have rig bars extending only between the top pair of chords or only between the bottom pair of chords.

Rig bars according to the disclosure may be stamped or otherwise marked with a load rating for the rig bar and/or truss section. Rig bars according to the disclosure may be fabricated with a suitable thickness, to achieve a desired load rating. While the present disclosure shows solid rig bars, it will be understood that in other embodiments, tubular rig bars may be used, with a rig bar according to the disclosure fabricated from a suitable material or with a suitable wall thickness to achieve a desired load rating.

The embodiment shown in FIG. 5 provides conventional connection pieces to couple to adjacent truss sections. In other embodiments, rig bars according to the disclosure may be used with truss sections having aluminum or steel fork and space connectors (typically referred to as ‘spigots’) for coupling to adjacent truss sections. In still other embodiments, rig bars according to the disclosure may be used with truss sections having end plates according to the disclosure, as described in more detail with reference to FIGS. 9A and 9B.

FIG. 6 provides an isometric detail view of connection elements used to suspend a truss 600 according to the first embodiment of the disclosure. The truss 600 includes chords 602 and rig bar 620 extending between the chords 602 and fixedly coupled at respective ends to the chords 602. A wire rope 604 is coupled directly to the rig bar 620 by a shackle 608. The body of the shackle 608 is passed through an eye of the wire rope 604. A threaded pin is passed through a first lug of the shackle 608, then through an aperture of the rig bar 620, and then screwed into the other lug of the shackle 608. The pin may be screwed into the shackle by hand or it may be further tightened using a wrench or other tool. In this way, the rig bar is adapted to receive without the use of tools a portion of a removable coupler operable to suspend the truss from above.

While FIG. 6 shows the shackle 608 coupled to the rig bar 620 extending between the top chords 602 of the truss section 600, in other embodiments a truss section according to the disclosure may be suspended by one or more shackles coupled as described above to rig bars extending between bottom chords of the truss section. In still other embodiments, a truss section according to the disclosure may be suspended by a plurality of shackles, where some shackles are coupled to rig bars extending between top chords of the truss section, and other shackles are coupled to rig bars extending between bottom chords of the truss section.

In further embodiments, rig bars may be positioned vertically, between a top chord and a bottom chord, to provide connection points for shackles on cables used to restrain horizontal motion of a truss section or truss according to the disclosure. In other embodiments, rig bars extending between either top chords or bottom chords of a first truss section according to the disclosure may receive shackles coupled to cables used to suspend other trusses or truss sections, speakers, screens, scenery, drapes, or other equipment from the first truss section.

FIG. 7 presents a detail view 700 of a portion of the truss section of FIG. 5. The chords 502 have circular cross sections. The rig bar 520 is solid and has a rectangular cross section, with a long dimension oriented vertically. The rig bar 520 is preferably ¾″ thick in the horizontal dimension. The rig bar 520 also has concave circular profiles 724 in each end (only one end is visible in FIG. 7). The concave circular profiles 724 have dimensions corresponding to the diameters of the chords 502 and are adapted to receive side portions of the chords 502. In other embodiments, the chords may have other cross sections and the rig bars have other concave profiles adapted to receive side portions of the chords.

FIG. 8 presents a second detail view 800 of a portion of the truss section of FIG. 5. The rig bars 520 are welded to the chords 502 by beads 830.

FIGS. 9A and 9B provide isometric views of a truss section 900 according to a second embodiment of the disclosure. Similar to the truss sections described with reference to FIGS. 3 and 4, the truss section 900 includes chords 902 and cross-bars 904 located near the ends of the chords 902. Unlike the truss sections described with reference to FIGS. 3 and 4, however, each cross-bar 904 is located with a surface substantially flush with, or extending outward from, the ends of its associated pair of chords 902.

An end plate 906 according to the disclosure includes ear portions 907 and apertures 908. (To make FIG. 9A less cluttered, reference characters indicate only two of the four ear portions 907 and two of the four apertures 908). The ear portions 907 extend from corners of the end plate 906 to cover the ends of each of the chords 902. The other end of the truss section 900 is similarly arranged to the end shown in FIG. 9B.

The ear portions 907 are adapted to prevent or minimize crushing or other damage to the ends of the chords 902 when the truss section 900 is dropped, dragged, collides with a wall, another truss section, or any other item, or is otherwise impacted. Such damage to the end of a chord can render a truss section unsafe for continued use, requiring the truss section to be removed from service, de-rated, or scrapped. The ear portions 907 thus may operate to extend the useful life of the truss section 900.

The end plates 906 are welded to the cross-bars 904 by beads 932 and beads 934. (Only three of the beads 932 and two if the beads 934 are visible in FIGS. 9A and 9B). An aperture 936 may be formed in the end plate 906 to reduce the weight of the end plate 906 without significantly reducing the structural strength of the end plate 906. The end plate 906 is preferably a ⅜″ aluminum plate.

The end plate 906 is stronger than the connection pieces 306A, 306B, and 406 described with reference to FIGS. 3 and 4. This enables trusses assembled from a plurality of truss sections 900 to bear greater loads than trusses assembled from truss sections 300 and 400, described with reference to FIGS. 3 and 4.

The end plates 906 are the same thickness as the legs of the connection pieces 306A, 306B, and 406, but the end plate 906 includes more material, resulting in a stronger mechanical coupling between truss sections. Additionally, there is more contact area between the end plates 906 on adjacent truss sections than with connection pieces 306A, 306B, and 406, which may improve compression loading on the conjoined truss sections. Further, the welding pattern for the end plates 906 may use less welding material, however the placement of the welding beads may create a stronger connection between the end plates 906 and the cross-bars 904 than with connection pieces 306A, 306B, and 406. Still further, the welding pattern for the end plates 906 makes the end plates quicker to install than the connection pieces 306A, 306B, and 406, which may decrease manufacturing costs.

Additionally, the single plate 906 may be manufactured in a one-step process, which may decrease manufacturing cost from connection pieces 306A, 306B, and 406, which are typically manufactured in a three-step process. Further, the single endplate 906 replaces a plurality of conventional connection pieces, which may also decrease manufacturing costs.

FIGS. 10A and 10B provide isometric views of a truss section 1000 according to a third embodiment of the disclosure. Similar to the truss sections described with reference to FIGS. 9A and 9B, the truss section 1000 includes chords 1002 and cross-bars 1004 located near the ends of the chords 1002.

An end plate 1006 according to the disclosure includes ear portions 1007 and apertures 1008. The ear portions 1007 extend from corners of the end plate 1006 to cover the ends of each of the chords 1002. The end plates 1006 are welded to the cross-bars 1004 by beads 1032 and beads 1034. An aperture 1036 may be formed in the end plate 1006. The end plate 1006 is preferably a ⅜″ aluminum plate.

Different from the end plate 906 described with reference to FIGS. 9A and 9B, the apertures 1008 in the end plate 1006 are slots located on a diagonal between the chords 1002 and a longitudinal axis of the truss section 1000. The slotted apertures 1008 enable truss sections of differing sizes to be mechanically coupled. The truss section 1000 may be coupled to a truss section having a smaller cross section and connection pieces 306A, 306B, or 406, or end plates 906 or 1006.

The rig bars and end plates according to the disclosure may be used with any size truss or truss section. While the embodiments shown are all trusses and truss sections having square cross sections, it will be understood that the rig bars and end plates according to the disclosure may be used with trusses and truss sections having any shape cross section and any number of chords.

While the embodiments described herein are truss sections, it will be understood that other embodiments may be complete, un-segmented trusses. In some embodiments, rig bars according to the disclosure may be used in a complete truss that does not have connection pieces or end plates. In other embodiments, a truss section having rig bars and/or end plates according to the disclosure may be used as a complete truss in one application and combined with other truss sections in other applications.

Although the present disclosure has been described with exemplary embodiments, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims. 

What is claimed is:
 1. A method of fabricating a truss section, the method comprising: connecting a plurality of cross-bars to a corresponding plurality of truss chords, each cross-bar extending between an associated pair of truss chords in the plurality of truss chords, each cross-bar located adjacent to an end of the truss section; and after the plurality of cross-bars have been connected to the corresponding plurality of truss chords, fixedly coupling an end plate to the cross-bars, the end plate having a first plurality of apertures and a plurality of ear portions, wherein each of the plurality of ear portions extends from the end plate to cover a corresponding end of one truss chord of the plurality of truss chords, and the first plurality of apertures are configured to align with a corresponding second plurality of apertures in an end plate or connection piece of an adjacent truss section and are operable to receive a corresponding plurality of connectors that also pass through the second apertures to fixedly couple the truss section to the adjacent truss section.
 2. The method of claim 1, wherein connecting the plurality of cross-bars to the corresponding plurality of truss chords comprises coupling each cross-bar to the associated pair of truss chords with one surface of the cross-bar substantially flush with, or extending outward from, corresponding ends of the associated pair of chords.
 3. The method of claim 1, wherein fixedly coupling the end plate to the cross-bars comprises welding the end plate to the cross-bars.
 4. The method of claim 1, wherein at least one truss chord of the plurality of truss chords has a circular cross section and the ear portion corresponding to the at least one truss chord is adapted to prevent damage to the end of the at least one truss chord.
 5. The method of claim 1, wherein the end plate includes an additional aperture adapted to reduce a weight of the end plate.
 6. The method of claim 1, wherein at least one of the first plurality of apertures is a slot.
 7. A method of fabricating a truss section, the method comprising: connecting a plurality of cross-bars to a corresponding plurality of truss chords, each cross-bar extending between an associated pair of truss chords in the plurality of truss chords, each cross-bar located adjacent to an end of the truss section; fixedly coupling a first end of a rig bar to a first one of the plurality of truss chords; fixedly coupling a second end of the rig bar to a second one of the plurality of truss chords, the rig bar including an aperture adapted to receive without the use of tools a portion of a removable coupler operable to suspend the truss section from above; and after the plurality of cross-bars have been connected to the corresponding plurality of truss chords, fixedly coupling an end plate to the cross-bars, the end plate having a first plurality of apertures and a plurality of ear portions, wherein each of the plurality of ear portions extends from the end plate to cover a corresponding end of one truss chord of the plurality of truss chords, and the first plurality of apertures are configured to align with a corresponding second plurality of apertures in an end plate or connection piece of an adjacent truss section and operable to receive a corresponding plurality of connectors that also pass through the second apertures to fixedly couple the truss section to the adjacent truss section.
 8. The method of claim 7, wherein the first and second ends of the rig bar are fixedly coupled to the first and second ones of the truss chords at panel points of the truss section.
 9. The method of claim 7, wherein the first and second ones of the truss chords are located on a top side of the truss section.
 10. The method of claim 7, wherein the first one of the truss chords is located on a top side of the truss section and the second one of the truss chords is located on a bottom side of the truss section.
 11. The method of claim 7, wherein the rig bar has a rectangular cross section, the rectangular cross section having a long dimension oriented transverse to a long axis of the first one of the plurality of truss chords.
 12. The method of claim 7, wherein: the first and second ones of the plurality of truss chords have circular cross sections and the first and second ends of the rig bar have corresponding concave circular profiles to receive side portions of the first and second ones of the plurality of truss chords, respectively; and fixedly coupling the first and second ends of the rig bar to the first and second ones of the plurality of truss chords comprises welding the first and second ends of the rig bar to the first and second ones of the plurality of truss chords.
 13. The method of claim 7, wherein connecting the plurality of cross-bars to the corresponding plurality of truss chords comprises coupling each cross-bar to the associated pair of truss chords with one surface of the cross-bar substantially flush with, or extending outward from, corresponding ends of the associated pair of truss chords.
 14. The method of claim 7, wherein fixedly coupling the end plate to the cross-bars comprises welding the end plate to the cross-bars.
 15. The method of claim 7, wherein at least one of the first plurality of apertures is a slot. 